Around 9:45 p.m. Friday, the assailants walked into the store at 1737 Bay St. One suspect, wearing a mask and dark clothing, brandished a knife and demanded money, Costa said.

One of the two clerks reached under the counter to grab the hammer to defend himself. After the suspects left the store, one of the clerks jumped in his vehicle and chased the assailants along several streets in the South End until losing sight of them, Costa said.

The assailants are still at-large. Detectives are investigating. Anyone with information is asked to call the Fall River Police Department Major Crimes Division at 508-676-8511, or to call the anonymous tip line at 508-672-8477.

A maid who cleaned the home of former New England Patriots player Aaron Hernandez has testified at his murder trial that she saw him "messing with" the security camera in his basement the day after the killing.